Well, as amazing as In the Zone is vocally, production-wise, and lyric-wise, I still prefer Femme Fatale. Femme Fatale is a much more cohesive record than In the Zone and even though it lacks that artistic edge that In the Zone has, Femme Fatale is the definition of the perfect POP record.
Me Against the Music vs. Till the World Ends.
I Got That (Boom Boom) vs. Hold It Against Me.
Showdown vs. Inside Out
Breathe On Me vs. I Wanna Go.
Early Mornin' vs. How I Roll
Toxic vs. Drop Dead (Beautiful)
Outrageous vs. Seal It With A Kiss
Touch of My Hand vs. Big Fat Bass
The Hook Up vs. Trouble For Me
Shadow vs. Trip to Your Heart
Brave New Girl vs. Gasoline
Everytime vs. Criminal
EDIT: It also happens to be Britney's best reviewed album since ...Oops! I Did it Again.